Im working on posting to facebook on an ios app. I had it working fine but somehow it has stopped working. I have the users auth at this point and all thats fine it just keeps giving me this error when i try to post to facebook "the post's action links must be valid urls"
below is my code for the post

the post works if i remove the actionLinksStr from the params as the error says that the link within it is not valid. This has been working for months but just stopped when i tried it today and i cant seem to get it back working again. Has anyone any idea why this error would suddenly start happening with no change to the actual sharing code? the url im passing into the action link is definately valid. any help would be much appreciated thanks
edit: just gonna flag this as a bug on facebooks dev site. see if i can get any feedback from there. still a mystery to me